From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754615AbYIEOtL (ORCPT ); Fri, 5 Sep 2008 10:49:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753415AbYIEOs4 (ORCPT ); Fri, 5 Sep 2008 10:48:56 -0400 Received: from ns1.q-leap.de ([153.94.51.193]:37865 "EHLO mail.q-leap.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753376AbYIEOs4 (ORCPT ); Fri, 5 Sep 2008 10:48:56 -0400 From: Bernd Schubert To: Arjan van de Ven Subject: Re: frame unwinder patches Date: Fri, 5 Sep 2008 16:48:52 +0200 User-Agent: KMail/1.9.9 Cc: linux-kernel@vger.kernel.org, Andi Kleen References: <200809051552.47929.bs@q-leap.de> <20080905071337.3373ab86@infradead.org> In-Reply-To: <20080905071337.3373ab86@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200809051648.52767.bs@q-leap.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 05 September 2008 16:13:37 Arjan van de Ven wrote: > On Fri, 5 Sep 2008 15:52:47 +0200 > > Bernd Schubert wrote: > > > (and if you really care it's 1 line of code to turn it off) > > > > It is not only this, I think the dwarf2 stack unwinder patches > > provide by far better traces than the in-kernel unwinder. At least > > ever since I applied these patches to our kernels, I was able to read > > the stack dumps... > > they really wouldn't be different than the ones you get if you remove > the "?" lines. Well may be, but then there is still the performace degrading, so I don't want to have it enabled on our production kernels. I admit I never measured what is the difference between of CONFIG_FRAME_POINTER=y and =n, but the fact the help text says there is a difference already makes me want to disable it (especially, since we have to provide benchmarks before we can sell a system). Cheers, Bernd -- Bernd Schubert Q-Leap Networks GmbH